Brake system



Feb. 18, 1936.

B. s. AIKMAN BRAKE ssTEM Filed July 2o, 19:54

ATTO!! Patented Feb. 18, 1936 BRAKE SYSTEM Burton S. Aikman,Wilkinsburg, Pa., assignor to The Westinghouse Air Brake Company,Wilmerding, Pa., a corporation of Pennsylvania Appiication July 20,1934, Serial No. 736,189

29 Claims.

This invention relates to electro-pneumatic brakes and nas for itsprincipal object to provide inertia controlled means for* controllingthe degree of brake application to such as will produce andsubstantially maintain a predetermined rate of retardation according tothe position of the brake controlling device within an operating zone.

Other objects and advantages will appear from the following moredetailed description of the invention.

In the accompanying drawing; Fig. 1 is a diagrammatic View, partly insection, of an electro-pneumatic brake equipment embodying theinvention; Fig. 2 is a sectional View taken on the line 2 2 of Fig. 1;and Fig. 3 is a diagrammatic development of the brake valve device,showing the connections established in various operating positions ofsaid device.

As shown in Fig. 1, the equipment may comprise a brake valve device I, aretardation controller de-vice 2 associated with said brake valvedevice, an application magnet valve device 3, a release magnet valvedevicey 4, a brake cylinder 5, an interlock magnet valve device B and amain reservoir l.

Referring to the drawing, the brake valve device may comprise a casing 8having a. valve chamber 9 containing the usual rotary valve i6 adaptedto be operated by a handle II through the medium of a stem I2.

The brake valve device is provided with a release position, a lapposition, an application zone in which, when operating electrically, thedegree of application is automatically limited in. accordance with theposition of the operating handle, Aand in which the brakes are adaptedto be appiied pneumatically upon failure of the electric current supply,and a special pneumatic application position in which the brakes may beapplied pneumatically upo-n failure of the application magnet, as willbe understood from the description hereinafter.

For automatically limiting the degree of brake application effected bythe brake valve device so as to limit the rate ofretardation to apredetermined degree varying according to the operating position of saiddevice, a retardation controller device 2 is provided, which maycomprise a hermetically sealed tube i 3 with upturned ends andcontaining a body of mercury I4, or other liquid which is a goodconductor of electric current, normally extending part way up into thespace at the upturned ends. Said tube is carried horizontally at the endof a shaft 36 rotatably mounted in a bracket I5 which extends from thecasing 8 of the brake valve device I, said tube being insulated fromsaid shaft. According to the preferred form of construction, the tube I3is made of some electrically insulating material, such for example, asglass, molded bakelite, hard rubber, or the like, which has smoothinterior walls, so as. to permit free movement of the body of liquid I4contained in said tube.

For positioning the retardation controller device 2 according to theoperating position of the brake valve device E, a gear segment I6 issecured to the stem l2 and has teeth adapted to engage the teeth of Y agear segment Il secured to the shaft 36.

Fixed to the gear segment II, in the present instance by means of ascrew I8, is a contact member I9, which may be in the form of a metallicplate electrically insulated from said gear segment by means of aninsulating member 20 and from said screw by means of an insulatingwasher 2I interposed between the head of said screw and the member I9.Carried by the contact member I9 is a Contact 22 which is adapted toengage a contact 23 which may be formed on the bracket I5, when theoperating handle H is turned to any position within the applicationzone. The contact member I9 is connected by a wire 24 to the retardationcontroller device and the contact 23 is grounded through the bracket I5,the casing 8 of the brake valve device and the ground wire 25.

Extending through the wall at one end of the tube I3 into the interiorof said tube is a contact 2E which is connected by a wire 21 to oneterminal of the application magnet valve device 3, the other terminal ofsaid device being connected by a Wire 28 to one terminal oi a manuallyoperated switch device 36, the other terminal of said switch devicebeing connected by a Wire 3| to a source of electric current supp-ly,such as the trolley wire 32. Extending through the wall at the other endof said tube into the interior thereof is a Contact 29 which isconnected by a Wire 33 toone terminal of the release magnet valve device4, the other terminal of said device being connected to the vvirey 28.`A contact 34 extends through the wall of the tube I3 into the interiorthereof at a point Where it is constantly submerged in the body ofliquid and is connected by the wire 24 to the contact memberl I9 and toa wire 35 which leads to the interlock magnet valve device 6. Thecircuit from the contact 26 tothe contact 34 and from the contact 29 to.the contact 34 is adapted to be controlled by the body of liquid I4, aswill be understood from the description hereinafter. The end of the tubecontaining the contact 29 will hereinafter be designated the A end andthe end containing the contact will hereinafter be designated the B end.

When the operating handle II is moved in a clockwise direction fromrelease position, the tube I3 of the retardation controller device 2 isrotated in a counterclockwise direction, the angularity of the axis ofsaid tube with reference to the longitudinal axis of the vehicle, or thedirection of motion of the vehicle, increasing according to the degreeof movement of said handle, but at no time during the movement of thehandle within the service zone will said axis be .disposed at rightangles to the direction of motion, for a reason which will be explainedhereinafter.

The disposition of the contact 26 with respect to the level of the bodyof liquid I4 in the tube i3 is such that when said tube has been rotatedto a position corresponding to the right hand limit of the applicationzone, said contact is submerged to such a depth that the drop in thelevel of said body of liquid at the B end of the tube, due to theforward movement of said body under the action of the force of inertiaas the speed of the Vehicle decreases, will not be suiicient to uncoversaid contact and thereby open the circuit from the contact 25 to thecontact 34 until and unless the rate of retardation exceeds apredetermined low degree. When the rate of retardation exceeds saidpredetermined low degree, then the level of the body of liquid at the Bend of said tube will fall until the level is sufficiently low touncover the contact 25 and thereby open the circuit from the contact 26to the contact 34.

The contact 29 is so disposed with reference to the level of the body ofliquid I4 that if the rate of retardation of the vehicle slightlyexceeds the rate at which the forward movement of said body uncovers thecontact 26, as above described, the resulting additional forwardmovement of said body of liquid will cause the contact 29 to becomesubmerged in said liquid and the circuit from the contact 29 to thecontact 34 will therefore be closed.

As the angularity of the tube I3 with reference to the direction ofmotion of the vehicle increases with the movement of the operatinghandle II in a clockwise direction from release position, aprogressively higher rate of retardation is required to cause suicientmovement of the body of liquid I4 to open the circuit from Contact 26 tocontact 34 and to close the circuit from contact 29 to contact 34. Thisis because the force of inertia acting on said body of liquid andtending te move same forward from the B end of the tube i3 to the A endthereof, as the speed of the vehicle decreases, being a component of theforce tending to move said body of liquid forward in the direction ofmotion of the vehicle, decreases as the angularity of said tube withrespect to the direction of motion increases. As a result, as saidangularity increases, a greater rate of retardation is required toobtain a component of suicient magnitude to change the level of the bodyof liquid suiciently to open the circuit at the contacts 2E and 34 andto close the circuit at the contacts 29 and 34. It will be understoodthat at no time during the movement of the handle I I Within the serviceZone is the tube I3 disposed at right angles to the direction of motionof the vehicle for the reason that in such a position of said tube, theabove mentioned component of the force of inertia would be zero, and theretardation controller device would therefore be rendered ineifective.

The application magnet Valve device 3 comprises a magnet 36 and a valve31 adapted to be operated by said magnet. The valve 31 ls contained in avalve chamber 38 which is connected to a pipe 39 leading to the mainreservoir 1 and said valve controls communication from valve chamber 38to a passage 49' leading to the release magnet valve device 4. A spring4I acts to normally maintain the valve 31 seated.

The release magnet valve device 4 comprises a magnet 42 and a valve 43adapted to be operated by said magnet. The valve 43 is contained in avalve chamber 44 which is open to passage 49 and which is connected to apipe 45 leading to the brake cylinder 5, and said valve controlscommunication from valve chamber 44 to an atmospheric passage 46. Aspring 41 acts on valve 43 for urging said valve to its seat.

The interlock magnet valve device comprises a magnet 48 and a valve 49containedin a valve chamber 59 and adapted to be controlled by saidmagnet. Said valve controls communication from a chamber 5I, which isconnected by' a passage and pipe 52 to the brake valve device, to apassage 53 Which communicates with a passage 54 leading through a pipe55 to the brake valve device and through a pipe 56 to the pipe 45. Aspring 15 acts to unseat the valve 49 when the magnet 48 is deenergized.One terminal of said magnet is connected by a wire 58 to the wire 28which, as hereinbefore mentioned, is connected to one terminal of themanually operated switch 39, while the other terminal of said magnet lsconnected by the wire 35 to the wire 24, which leads to the contactmember I9 associated with the brake valve device I.

In operation, uid under pressure supplied to the main reservoir 1 owsthrough pipes 39 and 51 and passage 51 in the brake valve device I tothe rotary valve chamber 9.

When the vehicle is at rest or is traveling at a constant rate of speed,the level of the body of liquid I4 in the tube I3 of the retardationcontroller device 2 is horizontal, as shown in Fig. I.

With the handle I I of the brake valve device I in release position, thecontact 22 is disengaged from the contact 23, so that, assuming that theswitch device 33 is in closed position, as shown in the drawing, thecircuit to the magnet 48 of the interlock magnet valve device, whichincludes the supply wire 32, wire 3|, the switch device 30, wires 28 and58, the magnet 48, wires 35 and 24, contact member I9, contacts 22 and23, the casing 8 of the brake valve device, and wire 25, is open at thecontacts 22 and 23, so that the magnet 48 is maintained deenergized.With said magnet deenergized, thevvalve 49 is held unseated by thespring 15, so that the brake cylinder 5 is open to the atmospherethrough pipes 45 and 56, passages 54 and 53, valve chamber 50, past thevalve 49, thence through chamber 5I, passage and pipe 52, passage 59 inthe brake valve device, cavity 69 in the rotary valve I9, and theatmospheric passage 6I.

If it is desired to effect an application of the brakes, the operatinghandle II is turned from release position to any position within theapplication zone, depending upon the degree of brake applicationdesired, or the rate of retardation desired, as will be understood fromthe description hereinafter. 'I'his movement will cause the tube I3 ofthe retardation controller device 2 to be rotated in a counterclockwisedirection from the position shown in Fig. 2, due to the meshingengagement of the gear segments I6 and Il, to a predetermined positioncorresponding to the position of the handle II, the A end of said tubebeing forward and the B end thereof rearward.

With the handle II turned to a position in the application zone, thecontact 22 is moved into engagement with the contact 23 so that thecircuit tothe application magnet 36 is closed, which circuit includesthe supply Wire 32, wire 3I, the switch device 30, wire 28, the magnet36, wire 21, contact 26, the body of liquid I4, contact 34, wire 24,contact member I9, contacts 22 and 23, the brake valve casing 8, andwire 25. The application magnet 36 is thus energized, so that the valve3l is unseated. With the valve 37 unseated, fluid under pressure issupplied from the main reservoir 'I to the brake cylinder 5 through pipe39, valve chamber 38, past the valve 3`I, passage 49, valve chamber 44in the release magnet valve device 4, and pipe 45, thereby eiecting anapplication of the brakes.

As the vehicle decelerates, the force of inertia will act upon the bodyof liquid I4 in the tube I3 to move it forward from the B end thereoftoward the A end. The consequent change in the level of said body ofliquid relative to the contacts 26 and 29, in any given rotationalposition of the tube I3, will depend upon the rate of retardation of thevehicle. If the rate of retardation exceeds a predetermined degree, thebody of liquid will be moved forward in the tube until the level in theB end thereof falls below the contact 26, thereby opening the abovementioned circuit to the application magnet 38. The resultingdeenergization of said magnet permits the valve 3l to be seated by thespring 4I, thereby cutting ol further supply of fluid under pressure tothe brake cylinder.

As the speed of the vehicle reduces, the coeflicient of friction betweenthe brake shoes and the car wheels increases and the rate ofretardation, and therefore the force of inertia acting on the body ofliquid I4, increases. The increased force acting on the body of liquidwill cause said body to move forward in the tube I3, thereby raising thelevel of the liquid in the A end thereof until the Contact 29 issubmerged. With said contact submerged, the magnet 42 of the releasemagnet valve device 4 is energized through a circuit which includes thesupply wire 32, wire 3|, the switch device 39, wire 28, the magnet 42,wire 33, contact 29, the body of liquid I4, contact 34, wire 24,co-ntact member I9, contacts 22 and 23, the brake valve casing 8, andthe ground wire 25. The energization of said magnet causes the valve 43to be unseated, thereby permitting fluid to be released from the brakecylinder 5 through pipe 45, valve chamber 44, past the valve 43, andthence through the atmospheric passage 46.

When the braking force has thus been reduced to a degree where the rateof retardation is insufficient to maintain the level of the body ofliquid I4 at the A end of the tube above the contact 29, the resultingdrop in the level of the body of liquid I4 at said end of the tube willcause the above described circuit tol the release magnet 42 to beopened. The resulting deenergization of said magnet permits the valve 43to be seated by the action of the spring 4'I, thereby cutting off theventing of fluid from the brake cylinder, so that the brakes are lapped.

If the rate of retardation should again increase so that contact 29 isagain submerged in the body of liquid I4, a further release of fluidunder pressure from the brake cylinder will be effected. If, however,the rst or any subsequent release of fluid pressure from the brakecylinder effects a rate of retardation such that the level of the bodyof liquid I4 will rise at the B end of the tube I3 until the contact 26is again submerged, the application magnet 36 will again be energizedand effect a further supply of fluid under pressure to the brakecylinder 5, until the rate of retardation has again been increased to adegree suflicient to cause the body of liquid to open the circuit atsaid contact.

' Obviously, if fluid should leak from the brake cylinder suflicientlyto cause a decrease in the rate of deceleration which will effect thesubmergence of the contact 26, uid under pressure will again be suppliedto the brake cylinder.

As hereinbefore explained, the angularity of the tube I 3 with respectto the direction of motion of the vehicle increases as the operatinghandle I I is moved in a clockwise direction through the applicationzone. Thus, for the reason hereinbefore set forth, the rate ofretardation required to open the circuit to the application magnet 36retardation being required when the handle is at the right hand limit ofthe application zone and a higher rate when the handle is in anyposition within the application Zone beyond said limit, being greatestwhen the handle is at the left hand limit of said zone.

From the foregoing, it is apparent that when the operating handle II ismoved to a position for effecting an electric application of the brakes,the retardation controller device 2 operates to control the supply offluid under pressure to the brake cylinder and its release therefrom toa degree which will produce and substantially maintain a predeterminedrate of retardation of the vehicle, varying according to the angularityof the tube I3 with respect to the direction of motion of the vehicle.

It is apparent that as the vehicle approaches a stop, the rate ofretardation may be controlled by the manipulation of the operatinghandle Il, so that the vehicle may be brought to a stop smoothly.

To completely release the brakes, the operating handle I I is returnedto release position. This movement of the handle causes ythe contactmember I9, and thereby the contact 22, to' be rotated in a clockwisedirection, so that said contact is moved out of engagement with thecontact 23. With said contacts disengaged, the magnet 48 of theinterlock magnet valve device 6 is deenergized and the valve 49unseated, as hereinbefore described in connection with release positionof the handle I I. The valve 49 being unseated, fluid under pressure isreleased from the brake cylinder 5 through pipes 45 and 56, passages 54and 53, valve chamber 58, past the valve 49, chamber 5I, passage andpipe 52, passage 59 in the brake valve device I, cavity 69 in the rotaryvalve I0, and the atmospheric passage 6I.

As hereinbefore explained and as shown in Fig. 3, when the operatinghandle II is moved into the application zone, the contact 22 is movedinto engagement with Contact 23. Due tol this engagement, the magnet 48of the interlock magnet valve device 6 is energized from the wire 28through a Ycircuit which` includes the wire 5.8, .the

62 in the rotary valve Ill of the brake valve device I connects passage59, leading through pipe and passage 52 to chamber 5I in the interlockmagnet valve device E, with` the rotary valve chamber 9, so that fluidunder pressure is supplied from said rotary valve chamber to chamber 5I.The valve 49 being seated, however, duid under pressure in chamber 5I isprevented from flowing therefrom past said valve into passage 53 andthence through passage 54, and pipes 55 and 45 to the brake cylinder 5.

Ii", with the handle I I in the application zone, the supply of electriccurrent should fail for any reason, the application magnet valve device3 will be rende-red inoperative to supply fluid under pressure to thebrake cylinder, but the brakes will automatically be appliedpneumatically because, due to the failure of the electric currentsupply, the magnet i8 of the interlock magnet valve device 6 will becomedeenergized and permit the valve 49 to become unseated by the pressureof the spring I5 and of the fluid in chamber 5l. With said valveunseated, fluid under pressure supplied to chamber 5I from the rotaryvalve chamber S flows therefrom to the brake cylinder through passages53 and 54 and pipes 56 and Q5, thereby effecting an application of thebrakes. Obviously, with the supply of electric current cut off, theretardation controller device 2 is inoperative tof control theretardation of the vehicle.

To release the brakes following an application effected pneumatically asabove described, the operating handle II is turned` to release positionand fluid under pressure is thereupon released from the brake cylinder 5through the interlock magnet valve device 6 and the brake valve devicein the same manner as hereinbefo-re described in connection with arelease of the brakes following an application effected electrically,The brakes will thereafter be controlled pneumatically in the usualmanner until the supply ci electric current is restored.

Should the application magnet 36 fail to operate when the operatinghandle II is moved into the application zone for eifecting an electricbrake application, the valve 3l will not be unseated to supply fluidunder pressure to the brake cylinder. In this event, the operator willturn the handle Il to the special pneumatic application position, inwhich iluid under pressure is supplied from the rotary valve chamber 9of the brake valve device I to the brake cylinder 5 through a port 63 inthe rotary valve Ill, passage and pipe 55, passage 54 in the interlockmagnet valve device 6, and pipes 56 and 45.

While one illustrative embodiment of the invention has been described indetail, it is not my intention to limit its scope to that embodiment orotherwise than by the terms of the appended claims.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is:

, 1. In a fluid pressure brake, the combination with a brake cylinder,of means operative electrically for supplying fluid under pressure tothe brake cylinder, manually operable means controlling a communicationthrough which fluid under pressure is supplied to the brake cylinder andfor effecting the operation of said electrically controlled means, andmeans effective upon energization vof said electrically controlled meansto cut off the flow of fluid under pressure through said communication.

2. Ina fluid pressure brake, the combination with electricallycontrolled means for supplying fluid under pressure to effect anapplication of the brakes, of manually operable means operative tosupply fluid under pressure to effect an application of the brakes andto elfcct the operation of said electrically controlled means, and meanseffective upon energization of said electrically controlled means forcutting off communication through which said manually operable meanssupplies fluid under pressure.

3. In a fluid pressure brake, the combination with a brake cylinder anda pipe through which fluid under pressure is adapted to be supplied tosaid brake cylinder, of means operative electrically to supply fluidunder pressure to said brake cylinder, manually controlled meansoperative to effect operation of said electrically operative means andto simultaneously supply fluid under pressure to said pipe, and meansenergized upon energization :of said means operative electrically forrendering said manually operated means ineffective to supply fluid underpressure to said pipe so long as the means operative electricallyremains energized.

4. In a fluid pressure brake, the combination with a brake cylinder anda pipe through which fluid under pressure is adapted to be supplied tosaid brake cylinder, of means operative electrically to supply fluidunder pressure to said brake cylinder, manually controlled meansoperative to t effect operation of said electrically operative means andto simultaneously supply fluid under pressure to said pipe, and meansoperative upon the operation of said manually operated means forrendering said manually operated means ineffective to supply fluid underpressure to said pipe so long as the means operative electricallyremains operative.

5. In a iluid pressure brake, the combination with a brake cylinder anda pipe through which fluid under pressure is adapted to be supplied tosaid brake cylinder, of means operative electrically to supply fluidunder pressure to said brake cylinder, manually controlled meansoperative to effect operation of said electrically operative means andto simultaneously supply fluid under pressure to said pipe, andelectrically controlled means adapted to be energized upon the movementof said manually operated means for rendering Vsaid manually operatedmeans ineffective to supply fluid under pressure to said pipe so long asthe means operative electrically remains operative.

6. In an electro-pneumatic brake, the combination with a brake cylinderand a pipe through which fluid under pressure is adapted to be suppliedto said brake cylinder, of electrically controlled means for supplyingfluid under pressure to said brake cylinder, a manually operated brakeswitch device for controlling the operation of said electricallycontrolled means, a valve operative to effect the supply of fluid underpressure to said pipe upon movement of said brake switch device to aposition for effecting operation of said electrically controlled means,and means operative to render said valve ineffective to supply fluidunder pressure to said pipe so long as the electrically controlled meansremains operative,

7. In a fluid pressure brake, the combination with a brake cylinder anda pipe through which fluid under pressure is adapted to be supplied tosaid brake cylinder, of means operative electrically to supply uid underpressure to said brake cylinder, manually operated means having aposition for eiecting operation of said electrically operative means andfor simultaneously supplying fluid under pressure to said pipe andhaving another position for supplying fluid under pressure to said pipe,and means for rendering said manually operated means inelective tosupply uid under pressure to said pipe in the iirst mentioned positionso long as the electrically controlled means remains operative.

8. In a fluid pressure brake, the combination with a brake cylinder anda pipe through which fluid under pressure is adapted to be supplied tosaid brake cylinder, of means operative electrically to supply fluidunder pressure to said brake cylinder, manually operated means having aposition for effecting operation of said electrically operative meansand for simultaneously supplying fluid under pressure to said pipe andhaving another position for supplying fluid under pressure to said pipe,and electrically controlled means adapted to be energized upon themovement of said manually operated means to the rst mentioned positionfor rendering said manually operated means ineffective to supply fluidunder pressure to said pipe in said position so long as the electricallycontrolled means remains operative.

9. In a vehicle brake apparatus, the combination with means foreffecting an application of the brakes, of a control device comprising avmobile body movable at all times in a horizontal direction upon achange in the rate of speed of the vehicle for controlling the operationof said means, and means for varying the angularity of the direction ofmotion of said body With respect to the direction of motion of thevehicle whereby said body controls said means to eiect a degree of brakeapplication which will produce and substantially maintain apredetermined rate of retardation of the vehicle, varying according tosaid angularity.

10. In a vehicle brake apparatus, the combination With means foreffecting an application of the brakes by uid under pressure, of adevice operable according to the rate of retardation of the vehicle forcontrolling the supply of fluid under pressure to effect an applicationof the brakes, means for supplying fluid under pressure to effect anapplication of the brakes until said device operates at a predeterminedrate of retardation to cut off the further supply of fluid underpressure, said device including a mobile body movable by inertia in ahorizontal direction, and means for varying the angularity of thedirection of motion of said body with respect to the direction of motionof the vehicle for varying the rate of retardation of the vehicle.

11. In a vehicle brake apparatus, the combination with means for eectingan application of the brakes by fluid under pressure, of a deviceoperable at a predetermined rate of retardation for cutting off thesupply of iluid under pressure, means for continuing the supply of fluidunder pressure until said device operates to cut off the supply of fluidunder pressure, said device including a mobile body movable by inertiain a horizontal direction, and means for varying the angularity of thedirection of motion o-f said body with respect to the direction ofmotion of the vehicle for varying the point at which said device cutsolf the supply of fluid under pressure.

12. In a vehicle brake apparatus, the combination with a brake cylinder,of a device operable according to the rate of retardation of the vehiclefor controlling the supply of fluid under pressure to said brakecylinder to effect an application of the brakes, means for supplyingfluid under pressure to said brake cylinder to effect an application ofthe brakes until said device operates at a predetermined rate ofretardation to cut off the supply of uid under pressure to said brakecylinder, said device including a mobile body movable by inertia in ahorizontal directtion, and means for varying the angularity' of thedirection of motion of said body with respect to the direction of motionof the vehicle for varying the rate of retardation of the vehicle.

13. In a vehicle brake apparatus, the combination with a brake cylinder,of electrically controlled means operative upon energization to supplylluid under pressure to said brake cylinder to effect an application ofthe brakes and operative upon deenergization to cut off the supply offluid under pressure to said brake cylinder, a control device forcontrolling the operation of said means and operable to maintain saidmeans energized until the rate of retardation has increased to apredetermined degree whereupon said device operates to eectdeenergization of said means, said device comprising a mobile bodymovable by inertia in a horizontal direction, and means for varying theangularity of the direction of motion of said body with respect to thedirection of motion of the vehicle for varying the rate of retardationof the vehicle.

14. In a vehicle brake apparatus, the combination With electricallycontrolled means for applying the brakes, of an inertia devicecomprising a body of liquid, contacts associated With said vmeans andcontrolled by said body of liquid according to the movement thereof aseffected by a change in the rate of speed of the vehicle, and means forvarying the angularity of the direction of movement of said body ofliquid with respect to the direction of motion of the vehicle.

15. In a vehicle brake apparatus, the combination With means foreffecting an application of the brakes, of a control device comprising amobile body movable at all times in a horizontal direction upon a changein the rate of speed of 'the vehicle for controlling the operation ofsaid means, and means for varying the angularity of the direction ofmotion of said body with respect to the direction of motion of thevehicle whereby said body controls said means to limit the brakeapplication to a degree Which Will provide a predetermined rate ofretardation of the vehicle varying according to said angularity.

16. In a vehicle brake apparatus, the combination with means forapplying the brakes, of-a control device comprising a mobile bodyadapted to move at all times in a horizontal direction upon a change inthe rate of speed of the vehicle, means controlled by movement of saidbody for controlling the first mentioned means, and means for varyingthe angularity of the direction of motion of said body with respect tothe direction of motion of the vehicle for varying the operation of thefirst mentioned means.

17. In a vehicle brake apparatus, the combination With means forapplying the brakes, of a control device comprising a mobile bodyadapted to move at all times in a horizontal direction upon a change inthe rate of speed of the vehicle, means controlled by movement of saidbody for controlling the iirst mentioned means, and manually operatedmeans for varying the angularity of the direction of the motion of saidbody with respect to the direction of motion of the vehicle for varyingthe operation of the first mentioned means.

18. In a vehicle brake, the combination With means for applying thebrakes, of a control device comprising spaced contacts in a circuit tosaid means, a mobile body adapted to move at all times in a horizontaldirection upon a change in the rate of speed of the vehicle for engagingsaid contacts, and means for varying the angularity off the direction ofmotion of said body With respect to the direction of motion of thevehicle for varying the operation of the first mentioned means.

19. In a vehicle brake apparatus, the combination with a brake cylinder,of means operative to control the supply of fluid under pressure to saidbrake cylinder, a control device comprising a mobile body adapted toconstantly move in a horizontal direction upon a change in the rate ofspeed of the vehicle for controlling the operation of said means, andmeans for varying the angularity of the direction of motion of said bodyWith respect to the direction of motion of the vehicle for varying theoperation of the rst mentioned means.

20. In a vehicle brake apparatus, the combination with a brake cylinder,of means operative to control the release of fluid under pressure fromsaid brake cylinder, a control device comprising a mobile body adaptedto constantly move in a horizontal direction upon a change in the rateof speed of the vehicle for controlling the operation of said means, andmeans for varying the angularity of the direction of motion of said bodywith respect to the direction of motion of the vehicle for varying theoperation of the rst mentioned means. Y

2l. In a vehicle brake apparatus, the combination with abrake cylinder,of means for controlling the supply of fluid under pressure to andrelease of fluid under pressure from said brake cylinder, a mobile bodyadapted to be moved at all times in a horizontal direction by the forceof inertia for controlling the operation of said means, and means forvarying the angularity of the direction of motion of said body Withrespect to the direction of motion of the vehicle for varying theoperation of the first mentioned means.

22. In a vehicle brake apparatus, the combination with a brake cylinder,of electroresponsive means for controlling the supply of fluid underpressure to and release of fluid under pressure from said brakecylinder, a mobile body adapted to be moved at all times in a horizontaldirection by the force of inertia for controlling the operation of saidelectroresponsive means, and means for varying the angularity of thedirection of motion of said body With respect to the direction of motionof the vehicle for varying the operation of said electroresponsivemeans.

23. In a vehicle brake apparatus, the combination with electroresponsivemeans operative to control the application and release of the brakes, ofcontrol means for governing the operation of said electroresponsivemeans comprising a mobile body having a normal position for eiecting anapplication of the brakes and movable at all times in a horizontaldirection according to the rate of retardation of the vehicle rst t0 alap position and then to a brake releasing position, switch means forrendering said control means effective to control said electroresponsivemeans, and means for varying the angularity of the direction of motionof said body with respect to the direction of motion of the vehicle forVvarying the operation of said electroresponsive means.

24. In a vehicle brake apparatus, the combination With manually movablemeans operative to effect an application of the brakes according to thedegree initially desired, of a mobile body controlled by said means forvarying the degree of said brake application so as to limit the rate ofretardation of the vehicle to a predetermined degree, said body beingurged bythe force of inertia in the direction of motion of the vehicleand constrained to travel in a horizontal direction at an angle to saiddirection of motion according to the degree of movement of said manuallymovable means.

25. In a vehicle brake apparatus, the combination with manually movablemeans operative .to effect an application of the brakes according to thedegree initially desired, of a mobile body controlled by said means forvarying the degree of said brake application so as to limit the rate ofretardation of the vehicle to a predetermined v degree, said body beingmovable in a horizontal direction varying according to the degree ofmovement of said manually movable means.

26. In Va vehicle brake apparatus, the combination with a manuallyoperated brake controlling device Vfor electing an application of thebrakes according to the degree initially desired, of an inertia devicecomprising a body of liquid, and means controlled by said body of liquidaccording to the movement thereof for varying the degree of applicationeffected by said brake controlling device so as to limit the rate ofretardation of the vehicle to a predetermined degree.

V27. In a vvehicle brake apparatus, the combination with a brakecylinder, of means for initially effecting a supply of fluid underpressure to said brake cylinder, and a retardation controller devicecomprising a body of liquid for controlling said means and having aposition for rendering said means effective, said device being operableto render said means ineffective upon a predetermined movement of saidbody of liquid as effected by a change in the rate of speed of thevehicle and to maintain said means ineffective until said body of liquidhas returned to said position.

28. In a vehicle brake apparatus, the combination with a brake cylinder,an application magnet valve device operative upon energization to effecta supply of iiuid under pressure to said brake cylinder, a releasemagnet valve device operative upon energization to effect a release ofuid under pressure from said brake cylinder, and contacts associatedwith said devices, of a retardation controller device comprising a bodyof liquid for controlling said contacts, said body of liquid having aposition for submerging said contacts associated with said applicationmagnet valve device for effecting the energization of said device andbeing movable to another position upon the retardation of the vehicle atone rate for disconnecting said contacts associated with saidapplication magnet valve device, said body of liquid being movable toanother position upon a rate of retardation greater than said rate forsubmerging said contacts associated with said release magnet valvedevice for effecting energzation of said device and maintaining saidcontacts associated with said application magnet Valve devicedisconnected.

29. In a vehicle brake apparatus, the combination with means forapplying the brakes, of an inertia device comprising a mobile bodymovable at all times in a horizontal direction for controlling theoperation of said means, means for Varying the angularity of thedirection of motion of said body With respect to the direction of motionof the vehicle for varying the operation of said means, and means formanually controlling the application of the brakes in the event 5 thatsaid inertia device is ineiective.

BURTON S. AIKMAN.

